In certain heavy-duty machinery, such as cement mixers, a generally horizontal load shaft is driven through a speed-reducing gear train from a motor detachably mounted on the gear housing. This mounting is designed to facilitate replacement of worn parts and, with the motor shaft extending laterally into the housing, also enables the same to be constructed in a more compact manner for accommodation in a narrow space, e.g., between the driver's cab and the tumbler of a cement-mixing vehicle. The heavy-duty motor finds a firm support on a seating surface at the top of the gear housing.
In conventional drives of this nature, the gear train includes a bevel pinion journaled in a sleeve which is interposed between the motor and the seating surface of the gear housing. The presence of two separate attachments, namely the pinion mounting and the motor, creates difficulties during assembly since unavoidable manufacturing tolerances introduce dimensional differences which must be compensated with the aid of spacers or shims to ensure a proper mesh between the pinion and the bevel gear driven thereby.